Zidansek retired nearly two hours in because of a gastrointestinal illness. Zidansk took a medical timeout after the first set, when her blood pressure was checked. She was noticeably less energetic, and had another medical timeout after three games of the second set. But she fought on and finally quit when the result became inevitable.

Potapova, the 2016 Wimbledon junior champion, was rapt.

"I can't hold in my emotions any longer," Potapova said. "It's my dream to play a final at home before my fans, I'm so happy."